RAdmin port

The icon in front of the machines - as the ones in RAdmin viewer - I would assume that a green, checked ikon would confirm that RAdmin was ready to answer.

However, I'm not able to launch RAdmin on these (even though I know RAdmin is active). Does it only check for the default port? I can't find a way to set "default" port. If it detects that RAdmin is active - why not also detect on which port?
(I use different port because there is malware specialized on using RAdmin default port.)